The energy gap of a semiconductor is $1.10 \mathrm{eV}$ The maximum wavelength $(\mathrm{in} \stackrel{°}{\mathrm{A}})$ at which it starts energy absorption will be

What is the conductivity of a semiconductor if electron density ${\mathrm{n}}_{\mathrm{e}}=5\times {10}^{12} {\mathrm{cm}}^{-3}$ and hole density ${\mathrm{n}}_{\mathrm{h}}= 8 \times {10}^{13} {\mathrm{cm}}^{-3}$ ?   $( {\mathrm{\mu }}_{\mathrm{e}} = 2.3 {\mathrm{m}}^{2 }{\mathrm{v}}^{-1} {\mathrm{s}}^{-1}$ and ${\mathrm{\mu }}_{\mathrm{h}} = 0.01 {\mathrm{m}}^2 {\mathrm{v}}^{-1} {\mathrm{s}}^{-1} )$

In the given circuit, if the forward voltage drop for the diode is $0.5 \mathrm{V}$, the current will be

$\mathrm{Ge}$ and $\mathrm{Si}$ diodes conduct at $0.3 \mathrm{V}$ and $0.7 \mathrm{V}$ respectively. In the following figure if$Ge$  diode connections are reversed, the value of $V_0$ changes by :-

A sinusoidal voltage $E_0$ of peak value $200 \mathrm{V}$ is connected to a diode and a resistor $R$, as shown in the circuit, so that half wave rectification occurs. If the forward resistance of the diode is negligible compared to $R$, the rms voltage (in $\mathrm{volts}$) across $R$ is approximately

The current $i$ in the circuit given below, will be

The diode used in the circuit shown in the figure, has a constant voltage drop of $0.5 \mathrm{V}$ at all currents and a maximum power rating of $100 \mathrm{mW}$. What should be the value of the resistor $R$, connected in series with the diode, for obtaining maximum current?